There are no other planets known to have warm water oceans from which true
water cloud hurricanes can form. However, many astronomers and planetary
meteorologists believe gas giant planets such as Jupiter and Saturn exhibits
such storms. The principal candidate is the famous Great Red Spot (GRS) on
Jupiter, and the numeous whorls that surround it, where ammonia takes the
place of water. The GRS exhibits an anticyclonic circulation at its top, just
as tropical cyclones do at the top of the troposphere. Over 400 extrasolar
planets have been found to date, but no others are confirmed to have
convectively driven storms. However, there is every reason to believe such
storms exist on extrasolar planets as well.